Hot-air flue



(ModeL) T. J. BRADBEER.

HOT AIR PLUE.

No. 390,438. Patented Oct. 2, 1888.

WITNESSES UNiTnn fiT Tns PATENT Oriana.

THOMAS J. BRADBEER, OF DETROIT, MICHIGAN.

Hon-AIR FLU E.

FfiPECIFICATION forming part of Letters Patent No. 390,438, datedOctober 2:, 1888,

Application filed January 4, 1887. Serial No. 223.363. (Modem To aZZwhom it may concern:

Be it known that 1, Thomas J. BRADBEER, of Detroit, county of Wayne,State of Michigan, have invented a new and useful Improvementin Pipes;and I declare the following to be a full, clear, and exact descriptionof the same, such as will enable others skilled in the art to which itpertains to make and use it, reference being had to the accompanyingdrawings,which form a part of this specification.

My invention relates to a new and useful improvement in hot-air lines orwall-pipes for hot-air furnaces and indirect radiation of steamheat,steam-pipe coverings,&c.; and it consists, essentially, of thedevices and their combination, as hereinafter more fully described, andmore particularly'pointed out in the claim.

In the drawings forming a part ofthis specification, Figure 1 is avertical section illustrating my invention. Fig. 2 is a side elevation;Fig. 3, a plan view of one of the sections, and Fig. 4 a view of one ofthe sections in perspective, showing parts broken away. Fig. 5 is aseparate view of-the intermediate plate in section, and Fig. 6 aseparate view in section of one end of one of the sections. Fig. 7illustrates a modification.

I carry out my invention as follows:

One feature of my invention contemplates the construction of said finesin sections of any desired length, and preferably of varying lengths, sothat from an assortment of sections of different lengths any desiredextent of flue may be selected for any given location. It is my purpose,therefore, to so construct the flue in sections that a dealer or tinneror builder can carry in stock assorted lengths of sections, so that aflue of any desired length can be put together by use of the sectionswithout cutting or waste of material.

My invention also contemplates the construction of the sectionsthemselves and theof varying lengths, although sections of uniformlength may of course be used where they may constitute the entire finewithout cutting.

Each of said intermediate sections is constructed with an outer wall, a,and an inner wall, a, which may be mutually supported and connected inany proper manner, one wit-h another,to constitute a combined section,my object being to provide an airspace, a outside and surrounding thecentral or internal main fiue, A". The airspaces of the differentsections are made to communicate with each other to form a continuousairspace, a throughout the entire length of the Wall-pipe andsurrounding the flue A the entire length, of said pipe. For the purposeof engaging the different sections together end to end, the walls (t aat one end are united by an intermediate joining plate, a", flanged, asshown at a, to set over the adjacent edges of the walls at a, theportion intermediate the edges being depressed and provided with one ormore orifices, a, whereby the airspace a may communicate from onesection to another. This depression of the plate at a leaves a socket, obetween the adjacent walls a a to receive the adjacent end of thecorresponding section. The intermediate sections may thus each beprovided with asocket a at one end. The opposite end of the section isslightly compressed, as shown, to narrow the section at this point so asto permit its entranceinto the socket a of the adjacent section. Thiscompression is illust 'ated at a The ad jacent edges of the walls a aareturned in and hooked together, as shown at a". The flanges of theseedges thus turned in and engaged are perforated, as shown at a to affordcommunication of the air-space a with that of the connected sect-ion.Thus each section may be provided with a compressed end and a socketedend, and thus is adapted for union with an other section. As soconstructed and united, the inner faces of united sections are left substantially smooth and free from obstruction, so that the central flue,A, is free from all impediments to the free passage of the heated air.

The lower section, A of the wall-pipe of course needs only to beprovided for union at one end with an adjacent section, and is providedwith a collar, A, to connect with the furnace or radiator-box and admitthe heated air into the interior flue, A. The outer wall, a, is alsoperforated,as shown at a, to admit cold air into the air-space a. Itwill be seen that by this construction the air-space a" affordsprotection in the location of the wall-pipe, so that the heat from thefine A shall be radiated into the said air-space, and thereby allliability .of danger is effectually overcome from the presence of theheat in the flue A.

The upper section, A, of the wall-flue leading to the register-box isconstructed with an orifice, a", in the interior wall, a, to admit theair from the air-space a into the register, and thence find access withthe heated air in the flue A into the room. It will be observed that byperforating the lower section, as at a, to admit the cold air, andperforating the upper section, as at a, free circulation is providedthrough the air-space a. The air circulating through said space is ofnecessity heated in its passage and is delivered into the room afterbeing so heated, so that not only is the danger from overheating in theflue A overcome, but the very heat ordinarily occasioning such danger isutilized to heat the air circulating in the airspace a and thereby theheating capacity of the furnace or radiator is economized andutilized,while it also becomes a safety Wall-pipe. Each section iscompletein itself, an air-space a entirely surrounding the interiorhot-air duct or flue, A The outer wall of the airspace a" may beplastered over, and in making offsets no brick and mortar are requiredfor safety, permittingan offsetto be madeas quickly as a perpendicularrun. A horizontal run may also be made with equal facility. I

I do not limit myself to any given shape for 1 making the fine, and haveshown it both rectangular and round, as in Fig. 7. It may be made of anydesired shape without departing from the principle of my invention.

It is intended not only to use a pipe thus constructed for the purposesof a hot-air wallpipe; but my invention also contemplates the use of myimproved pipe as a steam-pipe covering protecting said steanrpipe fromthe air, thus preventing condensation, and also afi'ording protection towood-work adjacent thereto.

What I claim is- A hot-air pipe consisting of an inner hot-air flue andan outer airflue, the inner wall beveled outward and the outer wallbeveled inward at one extremity and the metal of each engaged with theother, forming a perforated cross-wall at the extreme end of the pipe,said pipe at its opposite end having the inner and outer walls united bya separate thickness of metal extending from the extreme edge of theouter wall, passing downward between the walls a short distance, thenceacross and outward again to the extremity of the inner wall, andperforated along its bottom or cross-wall portion, whereby there isformed a mortised cavity of double thickness, substantially asdescribed.

In testimony whereof I sign this specification in the presence of twowitnesses.

THOMAS J. BRADBEER.

Vitnesscs:

N. S. WRIGHT, M. B. ODoeHER'rY.

